The invention relates to the field of switchgears, in particular to a switch cabinet and a cabinet door interlocking device thereof. The cabinet door interlocking device comprises a spring bolt, a grounded interlocking part and a mechanism interlocking part, wherein the grounded interlocking part is matched with the spring bolt in a stopping way when a ground switch is in a non-grounding switch-on state in order to prevent the spring bolt to move to an unlocking position, and a cabinet door of the switch cabinet cannot be opened; and the mechanism interlocking part is matched with the spring bolt in a stopping way when a switching mechanism is in a switch-off state in order to prevent the spring bolt to move to the unlocking position, and the cabinet door of the switch cabinet cannot be opened as well. Compared with an existing cabinet door interlocking device, the cabinet door interlocking device disclosed by the invention has the advantages that the cabinet door can only be opened when the ground switch in the switch cabinet is in a grounding switch-on state and the switching mechanism is in the switch-off state, so that the problems of poor safety and poor reliability during repairing of the switch cabinet since the cabinet door interlocking device of the switch cabinet cannot ensure that the cabinet door of the switch cabinet can only be opened when the switching mechanism is in the switch-on state are solved.